The present invention relates to a method of forming a ferroelectric film, a ferroelectric memory, a method of manufacturing the ferroelectric memory, a semiconductor device, and a method of manufacturing the semiconductor device.
A ferroelectric memory (FeRAM) retains data by spontaneous polarization of a ferroelectric film used in a capacitor section. In recent years, a semiconductor device utilizing the ferroelectric memory has attracted attention.
Conventionally, a ferroelectric film having good characteristics is formed by crystallizing a ferroelectric material by a heat treatment at a high temperature. For example, a heat treatment at a temperature as high as 600 to 700° C. is necessary for crystallizing Pb(Zr,Ti)O3 (PZT), and a heat treatment at a temperature as high as 700 to 800° C. is necessary for crystallizing SrBi2Ta2O9 (SBT). The ferroelectric material is crystallized by using a heat treatment furnace, for example.
However, the heat treatment at a high temperature causes elements to be significantly damaged. For example, characteristics of a peripheral section such as an electrode deteriorate due to atom diffusion. In the case where other semiconductor devices such as transistors are integrated in a ferroelectric memory, characteristics of the transistors and the like deteriorate due to thermal load applied by the high-temperature heat treatment.